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Discussion Starter · #1 ·
2005 Chevy 1500 4x4 with 5.3L

I know this says only "Urgent, No start problems" to be posted here but I am new and don't know where else to post this question.

My air conditioning has stopped cooling and its so hot here both of my children are getting sick in my truck and i just cannot keep going on like this anymore!!!!!

My a/c clutch stays engaged no matter what the pressure or how much refrigerant. I have changed the orifice tube, 2 wire Low pressure switch and the three wire Pressure sensor and charged the system. The high side seems a high and the low side is high but like I said the compressor keeps on running no matter what! Unless I unplug the comp cycling switch (Low side switch).

If it wasn't for my kids this wouldn't be URGENT but they are just dying in this heat! Any help would be greatly appreciated. Thanks!
 

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Have you thought of a new compressor clutch...or just a whole new compressor? Most shops I've been to in the past don't charge you much to diagnose the problem. Just try to find a reliable shop near you. Stay away from the dealership if you can. They'll likely be much more expensive just for a diagnosis.
 

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2006 Chevy 2500HD CCSB LBZ
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Does it seem like its running and just not blowing cold air? if it isn't the compressor then it could be the mixer door. When was the last time it was rercharged?
 

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Discussion Starter · #5 ·
Does it seem like its running and just not blowing cold air? if it isn't the compressor then it could be the mixer door. When was the last time it was rercharged?
I just recharged it after replacing the orifice tube. The system is all running properly except for the compressor clutch. It is staying engaged. Of course its blowing hot air..
 

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Discussion Starter · #6 ·
what are youre press readings
After pulling vacuum it jumps up to 45-50 psi low side and 250-300 high side w/o refrigerant because the clutch is engaged. Charged up to spec the low side is well over 70 psi and then retards- the high side is 290-350 -Once again clutch engaged. If I unplug the low side switch to disengage the compressor clutch the readings are 50 psi low and 190-225 high side with refrigerant. Almost normal..

But It always blows hot!

Of course it does get a little cooler charged up but not much still blowing 80+ deg air.
 

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is your mixing door under dash moving?
 

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there's another door that opens to pull air accross heater core. make sure thats closed. Pinch off heater hose and see if it gets cooler inside. might be a bad heater control.
 

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Is the accumulator housing cold-? This almost sounds like you have it over filled with freon-- There should be a label on the compressor/accumulator for the amount of freon to add. Seems like I think it was less than 2 lbs. How much did you add-??
 

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Discussion Starter · #11 ·
there's another door that opens to pull air accross heater core. make sure thats closed. Pinch off heater hose and see if it gets cooler inside. might be a bad heater control.
Just asking but that wouldn't keep the compressor clutch to keep running and my readings to be off would it? I think my whole problem is that the comp clutch isn't cycling on and off. It just says on constantly no matter what i do causing the system to not cool properly keeping by such high pressures. I cant figure out how to get it to cycle correctly even though Ive changed the sensors, orifice tube and charged the system.
 

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Discussion Starter · #12 ·
Is the accumulator housing cold-? This almost sounds like you have it over filled with freon-- There should be a label on the compressor/accumulator for the amount of freon to add. Seems like I think it was less than 2 lbs. How much did you add-??

No its not over charged. 2.3lbs is spec. But it doesn't matter if there is no-ZERO refrigerant or the proper amount, the clutch stays engaged constantly.
 

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No its not over charged. 2.3lbs is spec. But it doesn't matter if there is no-ZERO refrigerant or the proper amount, the clutch stays engaged constantly.
I always thought spec was 1.6lbs....
 

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might have to change the comp. n clutch
 

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Pressure on the low side WILL depend on ambient temps.Say it is 95 degrees out,then the low pressure side should be 45-50Kpa,and no more.If you have it overcharged it will NOT cool.Sure you don't have a leak?When you did add refrigerant what did you use??
 

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the clutch will stay on when the * button in the cab is on too.....OH,a low side reading for pressure is ONLY accurate when the compressor is engaged BTW.....
 

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pull the ac relay. is it stuck?
 

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Sticker and manual calls for 2.3lbs but i can let it out or add more still no change.
Nope... UTILITY SPEC IS 2.3lbs.

UTILITY. Utility means tahoe, escalade, yukon etc. ;)

PICKUP TRUCK spec is 1.6lbs. You overcharged it.

ben
 

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Discussion Starter · #20 ·
I have charged it to 1.6lbs still no change
If i had too little refrigerant the clutch would/should not engage if i had 2 much it shouldn't engage. (I have evacuated the system and started the truck with a vacuum absolutely no-ZERO- refrigerant -and the clutch continuously runs w/o cycling) i have charged it to spec under charged it and over charged it but the clutch still continuously runs without cycling

I have replaced the relay with no change

i have replaced both inline sensors with no change

I have scanned the sensors and they are working properly.

I have checked for a wire short w/no luck.

my scan tool is showing codes B0164 and B0229 but have no idea what that has to do with the clutch not cutting on and off. Whats next? Any help would be greatly appreciated.. Tks
 
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